Director Paul Thomas Anderson has always been known for his esoteric films. In fact, he’s probably the most well-known current filmmaker to have trafficked solely in films that aren’t aimed at mainstream audiences.

Although the ads for his latest, Inherent Vice, make it seem like an accessible stoner comedy, it may be his most impenetrable film — and that’s saying something. At its center is Larry “Doc” Sportello (Joaquin Phoenix), a private eye and unabashed pothead in Southern California in 1970.

Doc is brought into a web of intrigue by his former girlfriend, Shasta Fay Hepworth (Katherine Waterston), who wants his help in preventing the man with whom she’s having an affair, Mickey Wolfmann (Eric Roberts), from being committed to a mental institution by his wife.

The ads for Inherent Vice make it seem like an accessible stoner comedy, but it may be Paul Thomas Anderson’s most impenetrable film — and that’s saying something.

The rest of the film is a meandering and seemingly never-ending series of investigations by Doc. Each lead opens multiple doors, all of which he delves into while in a haze and being hounded by detective Christian “Bigfoot” Bjornsen (Josh Brolin). The film is also narrated in dense fashion by Doc’s friend Sortilege (Joanna Newsom), and her soporific droning does more to confuse matters than enlighten.

Of course, the film is based on the book by Thomas Pynchon, who’s famous for his complex novels, so it shouldn’t be a surprise that the film is similarly complicated. But just because the source material is convoluted doesn’t mean that the story couldn’t have been adapted into something more understandable.

What’s so frustrating about the film is that it does contain a multitude of undeniably hilarious moments, as if Anderson wants to tease us with his ability to appeal broadly before diving back in to more inscrutable matters. The funny scenes help keep the film moving when it threatens to get bogged down, but not enough to make up for the less interesting parts.

At two-and-a-half hours, the film is comparable in length to other Anderson films like Boogie Nights, Magnolia and There Will Be Blood. The difference, at least in those first two films, is that they contained a massive number of characters that allowed for digressions into subplots without ever feeling like you were losing momentum. In Inherent Vice, each of Doc’s detours feels like he’s leading us further and further into a rabbit hole, one from which we can never get out.

To his credit, Phoenix keeps Doc appealing throughout so that we want to see him succeed in his quest, whatever that may be. He’s no Jeff Bridges in The Big Lebowski, but Phoenix holds his own. Brolin, Waterston and appearances from the likes of Maya Rudolph, Martin Short and Reese Witherspoon also rescue the film at times.

But no amount of acting prowess can save Inherent Vice from its tedious fate. Anderson may have known exactly what he wanted to accomplish with the film, but he failed to translate it.